US 11,236,788 B2Granted

Adjusting the system pressure for a clutch

AssigneeGKN Automotive AG

InventorsVolker Rene Ruiters, Andreas Langhanki, Rainer Brüning

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Abstract

Setting a system pressure for a hydraulically actuated clutch comprises a) Providing a system comprising a pump drivable by an electrically operated motor controlled by a control unit that senses a motor current and rotational speed and a system temperature is determined; b) a characteristic diagram is provided specifying values for at least the motor current and rotational speed for different system operating points; c) Accessing the characteristic diagram while operating a vehicle; d) Sensing at least the motor current and rotational speed at at least a first operating point and determining the system temperature; e) Comparing the values, acquired in step d) for the current and speed with the values for the current and rotational speed from the characteristic diagram according to step b); f) Adapting the characteristic diagram for the system on the basis of the parameters determined in step d).

Claims8

Dependent claims

A method for setting a system pressure for a hydraulically actuated clutch, comprising:

a) providing a system that includes a pump for feeding a hydraulic fluid, an electrically operated motor for driving the pump, and a control unit for operating and controlling the motor;
wherein at least one motor current and one motor rotational speed are sensed by the control unit;
wherein a temperature within the system is calculated or measured;
b) providing a characteristic diagram for the system;
wherein the characteristic diagram specifies values for at least the motor current and the motor rotational speed for different operating points of the system;
c) operating the system in a motor vehicle, wherein the control unit accesses the characteristic diagram;
d) sensing at least the motor current and motor rotational speed of the motor at at least a first operating point during the operation of the system and calculating or measuring the temperature within the system;
e) comparing the values, acquired in step d) for the motor current and motor rotational speed with the values for the motor current and motor rotational speed from the characteristic diagram according to step b);
and
f) adapting the characteristic diagram for the system on the basis of the parameters determined in step d);
wherein in step b) at least one of the following parameters is taken into account for each of the operating points:
i. current measuring error of the control unit as a function of the motor rotational speed;
and
ii. current measuring error of the control unit as a function of the temperature of the control unit;
wherein setting of the system pressure takes place exclusively using data determined in the system;
wherein the steps d) and f) are carried out periodically;
wherein a period between carrying out the steps d) and f) is variable and determined as a function of at least one of the following parameters:
time, operating duration, specific stressing of the system;
and
wherein the first operating point comprises starting the motor from a motor rotational speed of zero revolutions per minute.

17 more elements

A motor vehicle, at least having a drive unit, a clutch and a system which has at least one pump for feeding a hydraulic fluid, an electrically operated motor for driving the pump and a control unit for operating and controlling the motor;

wherein the clutch is arranged on a side shaft of the motor vehicle in order to transmit torques so that by closing the clutch an axle of the motor vehicle can be connected in a torque-transmitting fashion to the drive unit of the motor vehicle, wherein the system is operated by
a) providing a characteristic diagram for the system;
wherein the characteristic diagram specifies values for at least the motor current and the motor rotational speed for different operating points of the system;
b) operating the system in a motor vehicle, wherein the control unit accesses the characteristic diagram;
c) sensing at least the motor current and motor rotational speed of the motor at at least a first operating point during the operation of the system and calculating or measuring the temperature within the system;
d) comparing the values, acquired in step c) for the motor current and motor rotational speed with the values for the motor current and motor rotational speed from the characteristic diagram according to step a);
and
e) adapting the characteristic diagram for the system on the basis of the parameters determined in step a);
wherein in step a) at least one of the following parameters is taken into account for each of the operating points:
i. current measuring error of the control unit as a function of the motor rotational speed;
and
ii. current measuring error of the control unit as a function of the temperature of the control unit;
and
wherein setting of the system pressure takes place exclusively using data determined in the system;
wherein the steps d) and f) are carried out periodically;
wherein a period between carrying out the steps d) and f) is variable and determined as a function of at least one of the following parameters:
time, operating duration, specific stressing of the system;
and
wherein the first operating point comprises starting the motor from a motor rotational speed of zero revolutions per minute.

16 more elements

Dependencies are inferred from the claim text.